Automatic damper for stoves and furnaces



(No Model.)

0. L. RIDGWAY.-

AUTOMATIC DAMPER FOR S'TOVES AND FURNACES. No. 336,261. Patented Feb. 16, 1886.

WITN'ESEEE and JF F' TUR N. PETERS, Phnm-Lnhngnphcr, Washmghm. mt:

UNITED STATES PATENT OFFICE.

CHARLES L. RIDGWAY, OF BOSTON, MASSACHUSETTS.

AUTOMATIC DAMPER FOR STOVES A-ND FURNACES.

SPECIFICATION forming part Letters Patent No. 336.261. dated February 6. 18 6- I Application filed January 8, 1884. Serial No. 116,779. (No model.)

.clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification, in explaining its nature, in which Figure 1 is a perspective view showing the application and construction of my invention.

Fig. 2 is an enlarged view in vertical section, and Fig. 3 is aperspective view of the dampercasing. damper, and part of the connecting mechanism. V

This invention relates to that class of automatic regulators employing a metal,either in the form ofa tube or otherwise, which is extensible under heat.and whose endwise movement is transmitted by suitable connecting mechanism to a damperlocated in the smokepipe or escape-port of the furnace or stove, and whereby the damper is automatically operated and held in a certain predetermined position, so that after the starting of the fire a uniform and equable draft is automatically provided and maintained.

The invention relates especially to the specific construction of the devices herein shown and described.

Referring to the drawings, A represents a furnace provided with myautomatic attachment. B represents the extensible metal, which is made in the form of a tube, and preferablyis of copper. It is supported at its outer end by the metal sleeve b, which projects inward from the metal plate I), and preferably is cast therewith. This sleeve has a shoulder, b", against which the outer edge of theextensible tube comes in contact,and which acts as a stop, so that the expansion of the tube shall be in one direction only, and that is, in this case, inwardly or away from the plate b. Extending through this tube is the rod 0, which has the screw-thread c on its inner end, upon which is fitted the nut 0 and which extends through the hole in the plate b, and is connected with the lever c by means of the pivot c. This lever is pivoted to lugs 0 extending outwardly from the plate b. There is pivoted to its upper end the arm d, which connects the lever 0 directly with the arm op-- damper-spindle d. This connectingarm d has 5 its inner end shaped substantially as shown in Fig. 2, which bears upon the lug or projection b extending outwardly from the plate b, and thus forms the fulcrum of the lever-arln, for' as the lever moves either inward or outward the part (2* bears against the lug b and forms a fulcrum, and the lever is therefore a lever of the third order.

If desired, I can use between the end of the lever d and the connection with the damper the graduated regulator-bar e, which consists of a metal plate having a-number of holes, 6', in a vertical line, adapted to fit the end of the lever, and having at its upper end a hole, by which it is fastened to the connecting chain or arm operating the damper. This regulator may bear at its upper end the word "Cold and at its lower end the word Hot, and may have each of the intermediate holes numbered. By this device it is of course apparent that the damper can be set at any desired position, so that upon the expansion of the metal tube the damper shall be operated from that position instead of from an entirely closed position, so that if it is desired to have a slow fire the arm d would be engaged with one of the upper holes in the regulator, whereby the damper would be partly opened before the regulator is caused to act by the increase of heat in the furnace or stove; or, if desired to open the damper to such an extent that a moderate fire or heat only shall be maintained, then the connection between the arm d and the regulator would be at one of the holes mid way; and if it is desired to open the damper but a very little for the purpose of regulating the heat, then the connection would be between the bar and the lower holes of the regulator.

In operation the expansion of the tube causes the rod to be drawn inward, thereby pulling the lever 0 toward the plate or furnace and causing it to throw down the lever d, and thereby open the damper through connecting devices. The tube and rod may of course be of any suitable length, and are ICO passed from the easing into the air heating chamber of the furnace or stove, or into any other portion from which it is desired to regulate the damper. The damper F preferably is shaped substantially as shown in Fig. 3 that is, it is rectangular in form. the lower portion being a little wider than the upper portion-and it is adapted to lit the opening in box or casingf. It is pivoted atf to the side walls of t-he'casing. The portion of the casing about the upper. part of the damper projects beyond the damper somewhat, and may have a lip, f, against which the upper portion of the damper shall come in contact when in a Vertical position. There is attached to one of the rods forming the pivot theweighted arm above referred to, which is fastened to the chain or other device which connects it with the-regulator. This weighted arm acts in opposition to the regulator, and upon the con'- traction ofthe tube :13, because of the lowering of the heat, operates to close the damper or move ittoward a closed position.

The form of the casing 'to-which this dan per is attached is well. shown in Fig. '3, and itcomprises the upper collar, 9, and lower col-- Jar-, upon-which thefunnel orpipe fits, and an intermediate section,which is round upon the back,:and has the side sections carried forward parallel with each other to form the rec't angular damper-opening. It willbe observed that the plate I) has the projections b, in which are formed holes for the bolts or screws which fasten it to the casing of the furnace It will also be seen that the damper is pivoted on its horizontal median line, .and that when it is opened the upper portion is thrown in and the lower portion out, so that a-large cold'air inlet is provided, while at the same time the direct port or passage is not entirely closed, and therefore a provision is obtained for the escape of all gases when the damper iswide Y scribed.

Having thus fully described my invention, I claim and desire to secure by Letters Patent ofthe United States I 1. The combination, with the plate I), hav- 2. The combination,with theplateb,having earsc and projections b of-the tube B, at-

tached at one end to the plate I). the rod 0, 1o

cated within said tube and engaging the end opposite the plate b, having the screw-thread c, the nut 0 lever c, pivoted to ears 0 con- 

